Tuesday, September 22, 2009

Manufactured during the mid 1980s supposedly as a means to “transcend” the limitations of hi-fi speakers at that time, does the BBE Sonic Maximizer qualifies back then – and now – as hi-fi?

By: Ringo Bones

Now (as in 2009) derided by hardcore audiophiles and “soulful” electric guitar players, I did remember during my high-school days – i.e. the mid 1980s – that a black box with the letters BBE was both revered and coveted in domestic hi-fi circles in my neck of the woods. To the uninitiated – and those who have already forgotten – here’s a refresher of that used to be wonderful black-box known as the BBE Sonic Maximizer.

The letters BBE stands for Barcus-Berry Entertainment Incorporated – later called BBE Sound Inc. when they’re “iconic” black-box / audio processor that became widely used and endorsed by Heavy Metal musicians during the “Hair Metal” era of the late 1980s and early 1990s. The company is located at Huntington Beach, California. Around the middle of the 1980s, BBE Sonic Maximizers began to be widely used for audio recording, motion picture sound tracks, TV and radio broadcasting, and motion picture theatre sound systems. According to the audio processor’s creators, BBE Sonic Maximizers were primarily designed to improve the sonic clarity of virtually any reproduced sound by correcting / compensating for phase and amplitude distortions produced as your typical power amplifier drives a typical loudspeaker system.

My first hand experience of this device was back in 1987 when a rich high-school classmate with similar musical tastes as me got one from his dad while working in the US. It was the Barcus-Berry BBE Model 2002 signal processor, which sold around 500 US dollars at the time. The BBE signal processor was meant to be installed between the signal source(s) – we only had a cassette tape deck and a Technics Quartz Synth tuner at the time – and the power amplifier.

Though my memories of that particular BBE Sonic Maximizer was now somewhat hazy, I can still vividly remember that we often played a track called Digital Bitch by W.A.S.P. (We Are Sexual Perverts?) at the time - Unforgettable because Chris Holmes, Blackie Lawless and the rest of the band probably foresaw the rise of Paris Hilton and her famous antics on the Internet. And as one of the few Heavy Metal bands who gained a strong following in the Punk community – my high-school classmate was actually into Punk / New Wave at the time – W.A.S.P. gained fame (or is it notoriety?) in both camps. Rumor has it that W.A.S.P. were “discovered” by Ed McMahon during the first season of Star Search.

From my present perspective – being my present hi-fi set-up is composed mainly of Electro-Harmonix vacuum tube-equipped and high-speed wide-band solid state exotica. All I can say is that the BBE Sonic Maximizer is nothing more than a “lazy-EQ”. I mean it is just an adjustable Loudness controller on steroids – though I am not denying that it is not useful. Given that at the time, we can rarely crank up our hi-fi sets to “unamplified / no PA system” garage band sound levels. Those rare occations when we can play as loud as possible during my high-school days is usually reserved for band practice.

When you can only play your hi-fi below the actual sound pressure level the music was originally recorded, Loudness and other EQ / tone controls to compensate the Fletcher-Munson Equal Loudness Contour Curves inherent to how our ears perceive airborne sound. To my ears – back then as it is now (2009) – BBE Sonic Maximizers boosts the bass and treble frequencies of the audio signal, depending on how much it’s “process” knob is being cranked.

First impressions on using the BBE Sonic Maximizer usually results in “clarity” – i.e. the boosting of the high-frequency signals usually around 2-KHz to 3-KHz upwards. And this is why many novice hi-fi enthusiasts during the early 1990s who can only afford mass market mini component boom boxes to listen to their copies of Smells Like Teen Spirit by Nirvana became concerned over “tweeter failure”. Especially when the tweeters of their BBE-equipped boom boxes (which became commonly widespread around 1992) heats up when playing the iconic “Seattle Grunge” album that features very distorted electric guitar sound with boosted high-frequencies.

Due to its endorsement and use by top musicians, like Megadeth and Skid Row – guitarists Dave “The Snake” Sabo and Scotti Hill were known to use one - during the early 1990s. The folks at BBE Sound Inc. created a BBE Sonic Maximizer plug-in for PC-based recording, which started to gain popularity during the late 1990s. For domestic hi-fi use, the BBE Sonic Maximizer works very well with budget cassette tape decks that don’t carry the Nakamichi badge to make them sound more “natural”. BBE Sonic Maximizers also works very well to "improve" (...or is that to flatter?) the “sound quality” of FM stations that are seriously addicted to those OPTIMOD compressors. And data reduced digital music downloads like MP3s. But if it is up to me, I would rather use the vacuum tube-based Pultec Model EQP-1R studio equalizer. This vintage studio equalizer - probably dating back to The Beatles era Abbey Road Studios - has 12RX7 and 12RU7 preamplifier vacuum tubes that can put to shame the BBE in sound quality terms.

Unfortunately, BBE Sonic Maximizers are an anathema to vacuum tube hi-fi aficionados and “soulful” electric guitar players because they tend to make their gear sound like cheap solid state. Like a brand new 10,000-watt audio power amplifier with a manufacturer’s suggested retail price of 200 US dollars. Surprisingly, BBE Sonic Maximizers can often be found in pawnshops or other establishments that sell pre-owned music gear somewhere between 50 to 100 US dollars. So it is somewhat a cost-effective way for the curious and uninitiated to experiment – or experience first-hand - what this BBE audio processing brouhaha is all about.

Monday, September 14, 2009

Given that they’ve been used successfully in a number of excellent sounding hi-fi applications, is there really a right op-amp for your audiophile needs out there?

By: Ringo Bones

Yes it’s true, there really is such a thing as an audiophile grade integrated circuit operational amplifier or IC op-amp. And most of them are not necessary manufactured by Analog Devices like the AD845 and AD843. Or those by Burr-Brown which their dual op-amps that are specified to be fast enough to handle the RF energy present in Red Book CD digital to analog conversion are often used in bridge configuration in left / right analog outputs.

The quest for finding the best off the shelf IC op-amp probably started during the early 1990s. When major CD player manufacturers discovered – either by theoretical introspection or trial and error – that those high-speed op-amps made their 500 US dollar or so CD players sound closer to entry-level audiophile grade vinyl LP replay.

From the electronic engineer’s design standpoint, high-speed op-amps are a necessity in Red Book specification CD players. Sufficient slew rate ratings are a necessity to handle the quite large amounts of ultrasonic requantization noise - which is an unfortunate by-product of converting your 16-bit 44.1-KHz digital data into a reasonably smooth analog waveform that could sufficiently past muster as music. In my experience with the most widely used up-market “hi-fi” op-amps – namely the LM318 and the LF356 – which have very different personalities when used in an audiophile context. Although I used audiophile grade ceramic IC sockets with silver connectors to allow me to easily replace both op-amps for comparison.

Over the years, my countless experiences with the high-slew rate (50 volts per microsecond) LM318 suggests that this IC op-amp is well suited to audiophiles who like to listen to Classical Music - Or wants to reproduce the recorded hall acoustic of an opera recording accurately played back in his or her listening room. It even enhances – or exaggerates – the Classical Music-like hall acoustics of some tracks of The Gathering’s “How To Measure A Planet?” album.

One drawback of the LM318 op-amp though is that it doesn’t like very much the “relatively” high-capacitance interconnects often used in entry-level solid-state audio gear. Like Monster Cable’s mellow sounding M850i interconnect often used to tame the harshness of cheap solid-state audio systems. Resulted in a high-pitched squealing sound on rare occasions (guaranteed more than once) during turn on. Although easily remedied by turning off and turning on again your entry-level solid-state amp.

Even though from a technical standpoint, the LF356 has a much lower slew rate rating (12 volts per microsecond) in comparison to the LM318, it does audiophile-oriented things that the LM318 can only aspire to. The very high input impedance – about 1 trillion ohms - of the JFET input stage of the LF356 allows it to have a bass response that Rock Music aficionados since the time of Elvis strive for. The LF356 is also capable of driving large capacitive loads – up to 10,000 picofarad or 0.01 microfarad – with ease. Which makes it more suitable for driving high-capacitance mellow sounding interconnects used in entry-level solid state gear.

Sound quality wise, it is as if the designer of the LF356 op-amp want it to sound like what recording engineer Andy Johns wants the first four album of Led Zeppelin to sound like – i.e. the “John Bonham snare sound”. The LF356 also sound as if it is the first op-amp with a very musically ideal loudness control. It defeats the Fletcher-Munson contour curve characteristic of the human ear that makes us less sensitive to the bass and treble frequencies when listening at reduced sound volume levels. With the LF356, you’ll get the full works whether you’re playing at 65dB or 95dB sound pressure levels - not unlike the sound of Electro-Harmonix versions of 12AX7 preamplifier tubes.

Surprisingly, the LF356 does room sound too - Although not like the Classical Music concert hall portrayed by the LM318. The room sound produced by the LF356 is the “normal” unadorned type – typical recording studio or just a spacious venue. The LF356 also has better low-level sound retrieval in comparison to the LM318 because the LM318 tends to exaggerate the dynamic range of CDs that are recorded without Tom Lord-Alge levels of compression. Like Lunachick’s Binge and Purge album which the LF356 still manages to retrieve low-level details that are played back even softer by its higher slew rate counterpart.

Both can still benefit from a well-regulated plus and minus 15 volt split supplies though, given the inherent RF corruption of our contemporary power lines. Despite both IC op-amps often rated with a power supply rejection ratio of over 100dB at 50 to 60-Hz AC. Boutique capacitors like Rubicon Black Gate capacitors or Philips sourced French Blue capacitors also help improve sound quality to no end.

So there you have it, two op-amps that I have extensive experience with that could past muster as being audiophile certifiable. Although it is somewhat over simplistic to conclude that one prefers Rock, while the other op-amp prefers Classical. The sound quality of one is sufficiently different from the other that it is worth noting. Although the LF356 also has a gorgeous presentation with Orchestral Classical Music recorded during the Golden Age of Stereo.

Monday, September 7, 2009

In the current fashion “revival” of vacuum tube and discrete transistor usage in the hi-fi scene, are audio designs that use integrated circuit op-amps still considered hi-fi?

By: Ringo Bones

Integrated circuit – or IC – op-amps have a myriad of advantages over their discrete component-based counterparts other than space. Like extremely high input impedance, high common mode rejection ratio and high power supply noise rejection ratio just to name a few all in a very compact package. But in terms of ultimate sound quality, many top designers in the hi-fi world find the sound quality of most IC op-amps wanting.

Richard Fryer, founder and owner of Spectral Audio – one of the top manufacturers of cutting edge solid-state audio gear, who as recently as 1998 still insist on using discrete circuitry. As opposed to integrated circuit chips much of the time. Fryer and his design team at Spectral Audio had found out over the years that for critical signal applications, integrated circuits – or IC chips to you and me – simply don’t meet their quality standards. Although he and his design team had been constantly evaluating new integrated circuits and, to everyone’s credit, the IC chips are getting better and better through the years. Still in the rigorous evaluations that the design team at Spectral Audio does these “improved” IC chips simply can’t pass the microphone feed accurately. There’s so much musical information and life that is lost – according to Fryer. Even with the most premium integrated-circuit amplifiers, these integrated circuit packages are just not up to Spectral Audio’s needs in critical signal applications.

Even though most audio designers in the hi-fi world still insist on using discrete components, there are those who are adventurous enough to use IC op-amps in their cutting edge audio designs. Ron Sutherland is one of those high-end audio gear designers who isn’t afraid to use IC op-amps in his almost 7,000 US dollar Sutherland PH-1 phono preamplifier. Maybe it is because Sutherland has a degree in both electrical engineering and physics that made him courageous enough to use a number of Analog Devices instrumentation integrated circuit op-amps on his somewhat “pricey” but very good sounding phono preamplifier.

Another upmarket high-end audio gear that uses IC op-amps is Reflection Audio Design’s 4,700 US dollar (550 US dollar extra for a phono stage) OM1 preamplifier. The OM1 preamplifier is a high-speed, super wide-bandwidth design based on very high slew rate IC op-amps rated at 2,000 volts per microsecond slew rate. It is purported to be flat to 2 megahertz and able to maintain an absolute phase of plus and minus 0.5 degrees across the audio bandwidth (20 Hz to 20,000 Hz). The OM1 preamp by Reflection Audio Design is a very pretty two-chassis affair – if you include the matching 1,550 US dollar battery unit – with a high level of attention to detail. Like the use of curved circuit traces to avoid high-frequency signal reflection.

There are also budget high-end audio designs that used IC op-amps. Like the Super Pas 4 i preamp kit which famed Dynaco tube amp tweaker Frank Van Alstine sold in the early 1990s. Though this preamplifier is somewhat unique because it is a tube and op-amp IC hybrid. Comprising of two 12AX7 tubes and two AD845 (AD843) FET input op-amps in the output stage. And it is surprisingly affordable – in high-end audio terms – at 595 US dollars back in 1993.

In my personal experience, op-amp IC chips – when used properly – can achieve excellent results sound quality wise. Sometimes I wonder why all brand-name boom boxes being flogged in the “high-street” can’t achieve excellent sound quality that matches even cheap DIY hi-fi that uses op-amp chips. Even DIY-ers had achieved excellent results with these lowly audio devices. Most of these serving as a gateway to the wild blue yonder of high-end audio. Next time, I’ll be discussing my experiences with the most touted op-amps for audio use, the LF356 and the high slew rate LM318 in a DIY hi-fi context – replete with unapologetic tweaks.